content_script.js

/**
* Gets the HTML of the user's selection
*/
	function getSelectionHTML() {
	  var userSelection;
	  if (window.getSelection) {
		// W3C Ranges
		userSelection = window.getSelection ();
		// Get the range:
		if (userSelection.getRangeAt)
		  var range = userSelection.getRangeAt (0);
		else {
		  var range = document.createRange ();
		  range.setStart (userSelection.anchorNode, userSelection.anchorOffset);
		  range.setEnd (userSelection.focusNode, userSelection.focusOffset);
		}
		// And the HTML:
		var clonedSelection = range.cloneContents ();
		var div = document.createElement ('div');
		div.appendChild (clonedSelection);
		return div.innerHTML;
	  } else if (document.selection) {
		// Explorer selection, return the HTML
		userSelection = document.selection.createRange ();
		return userSelection.htmlText;
	  } else {
		return '';
	  }
	}
/**
* Listens for a request from the button in the browser.
* When it sees the getSelection request, it returns the selection HTML, as well as the URL and title of the tab.
*/
chrome.extension.onRequest.addListener(function(request, sender, sendResponse) {
    if (request.method == "getSelection"){
   var selection = window.getSelectionHTML(); 
      sendResponse({body: selection, url: window.location.href, subject: document.title});
	  }
    else
      sendResponse({}); // snub them.
});